package com.hmdp.service.impl;

import cn.hutool.core.bean.BeanUtil;
import com.hmdp.dto.Result;
import com.hmdp.entity.Voucher;
import com.hmdp.entity.VoucherOrder;
import com.hmdp.mapper.VoucherOrderMapper;
import com.hmdp.service.ISeckillVoucherService;
import com.hmdp.service.IVoucherOrderService;
import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
import com.hmdp.utils.RedisIdWorker;
import com.hmdp.utils.UserHolder;
import org.redisson.api.RLock;
import org.redisson.api.RedissonClient;
import org.springframework.aop.framework.AopContext;
import org.springframework.context.annotation.Bean;
import org.springframework.core.io.ClassPathResource;
import org.springframework.data.redis.connection.stream.*;
import org.springframework.data.redis.core.StringRedisTemplate;
import org.springframework.data.redis.core.script.DefaultRedisScript;
import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Transactional;

import javax.annotation.PostConstruct;
import javax.annotation.Resource;
import java.time.Duration;
import java.util.Collections;
import java.util.List;
import java.util.Map;
import java.util.concurrent.*;

/**
 * <p>
 *  服务实现类
 * </p>
 *
 * @author 虎哥
 * @since 2021-12-22
 */
@Service
public class VoucherOrderServiceImpl extends ServiceImpl<VoucherOrderMapper, VoucherOrder> implements IVoucherOrderService {
    @Resource
    private ISeckillVoucherService seckillVoucherService;
    @Resource
    private RedisIdWorker redisIdWorker;
    @Resource
    private StringRedisTemplate stringRedisTemplate;
    @Resource
    private RedissonClient redissonClient;

    private static final DefaultRedisScript<Long> SECKILL_SCRIPT;
    static {
        SECKILL_SCRIPT=new DefaultRedisScript<>();
        SECKILL_SCRIPT.setLocation(new ClassPathResource("seckill.lua"));
        SECKILL_SCRIPT.setResultType(Long.class);
    }
    private BlockingQueue<VoucherOrder> orderTasks=new ArrayBlockingQueue<>(1024*1024);
    private static final ExecutorService SECKILL_ORDER_EXECUTOR= Executors.newSingleThreadExecutor();

    @PostConstruct
    private void init(){
        SECKILL_ORDER_EXECUTOR.submit(new VoucherOrderHandler());
    }

    private IVoucherOrderService proxy;
    @Override
    public Result seckillVoucher(Long voucherId) {
        //获取用户
        Long userId=UserHolder.getUser().getId();
        //获取订单id
        long orderId=redisIdWorker.nextId("order");
        //执行lua脚本
        Long result=stringRedisTemplate.execute(
                SECKILL_SCRIPT,
                Collections.emptyList(),
                voucherId.toString(),userId.toString(),String.valueOf(orderId)
        );
        //2.判断结果
        int r=result.intValue();
        if(r!=0){
            //2.1不为0，代表没购买资格
            return Result.fail(r==1?"库存不足":"不能重复下单");
        }
//        //2.2为0，有购买资格，把下单欣信息保存至阻塞队列
//        VoucherOrder voucherOrder=new VoucherOrder();
//        //2.3订单id
//        long orderId=redisIdWorker.nextId("order");
//        voucherOrder.setId(orderId);
//        //2.4用户id
//        voucherOrder.setUserId(userId);
//        //2.5代金券
//        voucherOrder.setVoucherId(voucherId);
//        //2.6放入阻塞队列
//        orderTasks.add(voucherOrder);
        //获取代理对象
        proxy = (IVoucherOrderService) AopContext.currentProxy();
        //3.返回订单id
        return Result.ok(orderId);
    }

    //    @Override
//    public Result seckillVoucher(Long voucherId) {
//        //1.查询优惠券
//        SeckillVoucher voucher=seckillVoucherService.getById(voucherId);
//        //2.判断秒杀是否开始
//        if(voucher.getBeginTime().isAfter(LocalDateTime.now())){
//            //尚未开始
//            return Result.fail("秒杀尚未开始");
//        }
//        //3.判断秒杀是否已经结束
//        if(voucher.getEndTime().isBefore(LocalDateTime.now())){
//            return Result.fail("秒杀已经结束");
//        }
//        if(voucher.getStock()<1){
//            //4.库存不足
//            return Result.fail("库存不足");
//        }
//        Long userId=UserHolder.getUser().getId();
//        //synchronized (userId.toString().intern()){
//        //SimpleRedisLock lock=new SimpleRedisLock("order:"+userId,stringRedisTemplate);
//        //创建锁对象
//        RLock lock=redissonClient.getLock("lock:order:"+userId);
//        //获取锁
//        boolean islock=lock.tryLock();
//        if(!islock){
//            //获取锁失败，返回错误或重试
//            return Result.fail("不允许重复下单");
//        }
//        try{
//            //获取代理对象(事务)
//            IVoucherOrderService proxy=(IVoucherOrderService) AopContext.currentProxy();
//            return proxy.createVoucherOrder(voucherId);
//        }finally {
//            //释放锁
//            lock.unlock();
//        }
//
//        //}
//    }

    @Transactional
    public void createVoucherOrder(VoucherOrder voucherOrder){
        //5.一人一单
        Long userId=voucherOrder.getUserId();
        //5.1查询订单
        int count=query().eq("user_id",userId).eq("voucher_id", voucherOrder.getVoucherId()).count();
        //5.2判断是否存在
        if(count>0){
            //用户已经购买过了
            log.error("用户已经购买过一次了");
            return ;
        }
        //6.扣减库存
        boolean success=seckillVoucherService.update()
                .setSql("stock=stock-1")// set stock=stock-1
                //.eq("voucher_id",voucherId).eq("stock",voucher.getStock())
                .eq("voucher_id", voucherOrder.getVoucherId()).gt("stock",0)//where id=? and stock>0
                .update();
        if(!success){
            //扣减失败
            log.error("库存不足");
            return ;
        }
        save(voucherOrder);
    }

//    @Transactional
//    public Result createVoucherOrder(Long voucherId){
//        //5.一人一单
//        Long userId=UserHolder.getUser().getId();
//        //5.1查询订单
//        int count=query().eq("user_id",userId).eq("voucher_id",voucherId).count();
//        //5.2判断是否存在
//        if(count>0){
//            //用户已经购买过了
//            return Result.fail("用户已经购买过一次了");
//        }
//        //6.扣减库存
//        boolean success=seckillVoucherService.update()
//                .setSql("stock=stock-1")// set stock=stock-1
//                //.eq("voucher_id",voucherId).eq("stock",voucher.getStock())
//                .eq("voucher_id",voucherId).gt("stock",0)//where id=? and stock>0
//                .update();
//        if(!success){
//            //扣减失败
//            return Result.fail("库存不足");
//        }
//        //7.创建订单
//        VoucherOrder voucherOrder=new VoucherOrder();
//        //7.1订单id
//        long orderId=redisIdWorker.nextId("order");
//        voucherOrder.setId(orderId);
//        //7.2用户id
//        voucherOrder.setUserId(userId);
//        //7.3代金券
//        voucherOrder.setVoucherId(voucherId);
//        save(voucherOrder);
//        //8.返回订单id
//        return Result.ok(orderId);
//    }

        private class VoucherOrderHandler implements Runnable {
            String queueName = "stream.orders";

            @Override
            public void run() {
                while (true) {

                    try {
                        //1.获取消息队列中的订单信息 XREADGROUP GROUP g1 c1 COUNT 1 BLOCK 2000 STREAMS stream.order >
                        List<MapRecord<String, Object, Object>> list = stringRedisTemplate.opsForStream().read(
                                Consumer.from("g1", "c1"),
                                StreamReadOptions.empty().count(1).block(Duration.ofSeconds(2)),
                                StreamOffset.create(queueName, ReadOffset.lastConsumed())
                        );
                        //2.判断消息获取是否成功
                        if (list == null || list.isEmpty()) {
                            //如果获取失败，说明没有消息，继续下一次循环
                            continue;
                        }
                        //3.解析消息中的订单消息
                        MapRecord<String, Object, Object> record = list.get(0);
                        Map<Object, Object> values = record.getValue();
                        VoucherOrder voucherOrder = BeanUtil.fillBeanWithMap(values, new VoucherOrder(), true);
                        //4.如果获取成功，可以下单
                        handleVoucherOrder(voucherOrder);
                        //5.ACK确认 SACK stream.orders g1 id
                        stringRedisTemplate.opsForStream().acknowledge(queueName, "g1", record.getId());
                    } catch (Exception e) {
                        log.error("处理订单异常", e);
                        handlePendingList();
                    }
                }
            }

            private void handlePendingList() {
                while (true) {
                    try {
                        //1.获取pending-list中的订单信息 XREADGROUP GROUP g1 c1 COUNT 1 BLOCK 2000 STREAMS stream.order 0
                        List<MapRecord<String, Object, Object>> list = stringRedisTemplate.opsForStream().read(
                                Consumer.from("g1", "c1"),
                                StreamReadOptions.empty().count(1),
                                StreamOffset.create(queueName, ReadOffset.from("0"))
                        );
                        //2.判断消息获取是否成功
                        if (list == null || list.isEmpty()) {
                            //如果获取失败，说明pending-list没有消息，结束循环
                            break;
                        }
                        //3.解析消息中的订单消息
                        MapRecord<String, Object, Object> record = list.get(0);
                        Map<Object, Object> values = record.getValue();
                        VoucherOrder voucherOrder = BeanUtil.fillBeanWithMap(values, new VoucherOrder(), true);
                        //4.如果获取成功，可以下单
                        handleVoucherOrder(voucherOrder);
                        //5.ACK确认 SACK stream.orders g1 id
                        stringRedisTemplate.opsForStream().acknowledge(queueName, "g1", record.getId());
                    } catch (Exception e) {
                        log.error("处理pending-list订单异常", e);
                        try {
                            Thread.sleep(20);
                        } catch (InterruptedException interruptedException) {
                            interruptedException.printStackTrace();
                        }
                    }
                }
            }
        }

//    private BlockingQueue<VoucherOrder> orderTasks=new ArrayBlockingQueue<>(1024*1024);
//    private class VoucherOrderHandler implements Runnable {
//        @Override
//        public void run() {
//            while(true){
//
//                try {
//                    //1.获取队列中的订单信息
//                    VoucherOrder voucherOrder=orderTasks.take();
//                    //2.创建订单
//                    handleVoucherOrder(voucherOrder);
//                } catch (Exception e) {
//                    log.error("处理订单异常",e);
//                }
//            }
//        }
//    }

            private void handleVoucherOrder(VoucherOrder voucherOrder) {
                //1.获取用户
                Long userId = voucherOrder.getUserId();
                //2.创建锁对象
                RLock lock = redissonClient.getLock("lock:order:" + userId);
                //获取锁
                boolean islock = lock.tryLock();
                if (!islock) {
                    //获取锁失败，返回错误或重试
                    log.error("不允许重复下单");
                    return;
                }
                try {
                    proxy.createVoucherOrder(voucherOrder);
                } finally {
                    //释放锁
                    lock.unlock();
                }
            }
}

